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authorSiddhesh Poyarekar <siddhesh@redhat.com>2013-03-26 19:28:50 +0530
committerSiddhesh Poyarekar <siddhesh@redhat.com>2013-03-26 19:28:50 +0530
commit6f2e90e78f151bab153c2b38492505ae2012db06 (patch)
tree03965f28878b90725ad89572ae61993bff4ebdfd /sysdeps/powerpc/power4
parentfce14d4e9c6e08ad8c825fe88d8cbdac5c739565 (diff)
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Make mantissa type of mp_no configurable
The mantissa of mp_no is intended to take only integral values. This is a relatively good choice for powerpc due to its 4 fpus, but not for other architectures, which suffer due to this choice. This change makes the default mantissa a long integer and allows powerpc to override it. Additionally, some operations have been optimized for integer manipulation, resulting in a significant improvement in performance.
Diffstat (limited to 'sysdeps/powerpc/power4')
-rw-r--r--sysdeps/powerpc/power4/fpu/mpa-arch.h56
1 files changed, 56 insertions, 0 deletions
diff --git a/sysdeps/powerpc/power4/fpu/mpa-arch.h b/sysdeps/powerpc/power4/fpu/mpa-arch.h
new file mode 100644
index 0000000000..9007c9d0ca
--- /dev/null
+++ b/sysdeps/powerpc/power4/fpu/mpa-arch.h
@@ -0,0 +1,56 @@
+/* Overridable constants and operations.
+ Copyright (C) 2013 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program; if not, see <http://www.gnu.org/licenses/>. */
+
+typedef double mantissa_t;
+typedef double mantissa_store_t;
+
+#define TWOPOW(i) (0x1.0p##i)
+
+#define RADIX TWOPOW (24) /* 2^24 */
+#define CUTTER TWOPOW (76) /* 2^76 */
+#define RADIXI 0x1.0p-24 /* 2^-24 */
+#define TWO52 TWOPOW (52) /* 2^52 */
+
+/* Divide D by RADIX and put the remainder in R. */
+#define DIV_RADIX(d,r) \
+ ({ \
+ double u = ((d) + CUTTER) - CUTTER; \
+ if (u > (d)) \
+ u -= RADIX; \
+ r = (d) - u; \
+ (d) = u * RADIXI; \
+ })
+
+/* Put the integer component of a double X in R and retain the fraction in
+ X. */
+#define INTEGER_OF(x, r) \
+ ({ \
+ double u = ((x) + TWO52) - TWO52; \
+ if (u > (x)) \
+ u -= ONE; \
+ (r) = u; \
+ (x) -= u; \
+ })
+
+/* Align IN down to a multiple of F, where F is a power of two. */
+#define ALIGN_DOWN_TO(in, f) \
+ ({ \
+ double factor = f * TWO52; \
+ double u = (in + factor) - factor; \
+ if (u > in) \
+ u -= f; \
+ u; \
+ })